1. Field of the Invention
The present invention relates to a medical guide wire used for treatment of a vascular lesion or the like.
2. Description of Related Art
Conventionally, in the treatment of the vascular lesion such as a stenotic portion and a completely occluded portion of a blood vessel, a medical guide wire (hereinafter simply referred to as the guide wire) is used. On the guide wire, a single coil spring or the like is provided on a distal end portion or a coil spring having a double layered structure, including an inner coil into which a core is inserted and an outer coil concentric with the inner coil, is provided. The distal end portion of the guide wire is reached to the vascular lesion such as the stenotic portion and the completely occluded portion of the blood vessel to perform a radial dilation (radial expansion) treatment.
In such a case, since the guide wire is passed through the vascular lesion, a high rotation transmission performance from a proximal end side (rear side) to a distal end side, a perforation performance and a fatigue resistance against continuous use are required.
Patent Document 1 discloses, about the guide wire, a bending rigidity and other properties of the core about a portion located at the proximal end side than the coil spring of the distal end portion.
Patent Document 2 discloses, about the guide wire, the coil spring located at the distal end portion and formed as a double layered structure including an inner coil and an outer coil which are concentric with each other.    [Patent document 1] Japanese Patent No. 4623906    [Patent document 2] Japanese Patent Laid-Open Publication No. 08-317989